A new method for the determination of utratrace silver(I) by near field thermal lens spectrometry has been developed. This method is based on the silver(I) catalyzed discoloring reaction of bromocresol green oxidized...A new method for the determination of utratrace silver(I) by near field thermal lens spectrometry has been developed. This method is based on the silver(I) catalyzed discoloring reaction of bromocresol green oxidized by sodium persulphate in the presence of a, a-bipy as activator and Triton X-100 as sensitizer. The linear range of this method is 0~1.6 ng穖L-1 of silver. The detection limit is 2?0-2 ng穖L-1. The method has been applied to the determination of silver in lead power and photographic paper with satisfactory results.展开更多
The purity of the brazing alloys applied is necessary to be improved with the increasing cleanness of steel. Calcium is easily brought into the widely ased brazing alloy, Ag-Cu-Zn, during the producing process. This p...The purity of the brazing alloys applied is necessary to be improved with the increasing cleanness of steel. Calcium is easily brought into the widely ased brazing alloy, Ag-Cu-Zn, during the producing process. This paper aims at revealing the effect of calcium on the melting behavior of the brazing alloy. The thermal analysis kinetics of silver alloy with trace calcium was studied by using differential scanning calorimetry （ DSC ） , and the enthalpy peaks were analyzed by differential methods. The rate constant of phase transformation in the probable brazing temperature range goes up with increasing calcium content, according to the values of the apparent activation energy, E, and the frequeney constant, A. It is concluded that the calcium addition could improve the melting performance of Ag-Cu-Zn brazing alloy.展开更多
A new method for the determination of ultratrace silver(I) by near field laser thermal lens spectrometry has been developed. This method is based on the silver(I) catalyzed discoloring reaction of bromcresol green oxi...A new method for the determination of ultratrace silver(I) by near field laser thermal lens spectrometry has been developed. This method is based on the silver(I) catalyzed discoloring reaction of bromcresol green oxidized by so-dium persulfate in the presence of ,'-bipyridine as an activator and TritonX-100 as a sensitizer. The reaction mechanism was discussed. The linear range of the method is 0—1.6 ngmL-1 and the detection limit is 2×10-2 ngmL-1 for silver. The method has been applied to the determination of silver in lead powder and photographic paper with satisfactory results.展开更多
文摘A new method for the determination of utratrace silver(I) by near field thermal lens spectrometry has been developed. This method is based on the silver(I) catalyzed discoloring reaction of bromocresol green oxidized by sodium persulphate in the presence of a, a-bipy as activator and Triton X-100 as sensitizer. The linear range of this method is 0~1.6 ng穖L-1 of silver. The detection limit is 2?0-2 ng穖L-1. The method has been applied to the determination of silver in lead power and photographic paper with satisfactory results.
文摘The purity of the brazing alloys applied is necessary to be improved with the increasing cleanness of steel. Calcium is easily brought into the widely ased brazing alloy, Ag-Cu-Zn, during the producing process. This paper aims at revealing the effect of calcium on the melting behavior of the brazing alloy. The thermal analysis kinetics of silver alloy with trace calcium was studied by using differential scanning calorimetry （ DSC ） , and the enthalpy peaks were analyzed by differential methods. The rate constant of phase transformation in the probable brazing temperature range goes up with increasing calcium content, according to the values of the apparent activation energy, E, and the frequeney constant, A. It is concluded that the calcium addition could improve the melting performance of Ag-Cu-Zn brazing alloy.
基金Project supported by the Science Foundation (No. 99H07) of Shaanxi Province of China.
文摘A new method for the determination of ultratrace silver(I) by near field laser thermal lens spectrometry has been developed. This method is based on the silver(I) catalyzed discoloring reaction of bromcresol green oxidized by so-dium persulfate in the presence of ,'-bipyridine as an activator and TritonX-100 as a sensitizer. The reaction mechanism was discussed. The linear range of the method is 0—1.6 ngmL-1 and the detection limit is 2×10-2 ngmL-1 for silver. The method has been applied to the determination of silver in lead powder and photographic paper with satisfactory results.
